Dereck Chisora and Tyson Fury shook hands on a £100,000-bet on the outcome of their heavyweight rematch on July 26 during a heated press conference on Monday.
The British and European titles will both be up for grabs in Manchester when the pair clash for the first time since Fury beat Chisora on points in 2011.
After delivering a barrage of personal insults at his opponent, the Londoner offered £10,000 as the winner-takes-all bet only for the challenger to insist he would give that amount to his two children to go shopping!
Fury then suggested that £100,000 was worth it and the pair shook on the new bet befor tempers boiled over and the conference was brought to an end.
Earlier Fury said: "For me this is nothing more than a stepping-stone fight.
"This is Dereck Chisora's final crack at the whip - but for me this is a stepping stone.
"Dereck Chisora is a journeyman, what champions do to journeymans is they smash them to bits.
"If I can't smash him to bits then I must be a journeyman too."
Undefeated Fury took Chisora's British and Commonwealth titles when he won at Wembley Arena three years ago, as well as ending his opponent's unbeaten record.
The 6ft 9in fighter insists, however, the British and European belts mean nothing to him and promises to hand them back to Chisora even if he wins.
"His European title and his belts - I'm not interested in them, I'm giving them back after I beat him," Fury said.
"He's the challenger, he's the chump and he's 10 levels below me and I'm going to prove that by smashing his face right in.
"Every time he thinks of Tyson Fury in the future he's going to wish he'd never heard that name.
"I'm going to annihilate him. He's going to sleep for good. There's no doubt in my mind. I'm flattening his big, ugly, fat face.
"He's the ugliest man I've ever seen, he can't talk, he's useless, the only thing he's got about him is he's a bit tough and he comes forward and swings some shots."